Apply automatic rubocop fixes

lib/code_ocean/config.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module CodeOcean
   class Config
     def initialize(filename)
@@ -7,10 +9,10 @@ module CodeOcean
     def read(options = {})
       path = Rails.root.join('config', "#{@filename}.yml#{options[:erb] ? '.erb' : ''}")
       if ::File.exist?(path)
-        content = options[:erb] ? YAML.load(ERB.new(::File.new(path, 'r').read).result) : YAML.load_file(path)
+        content = options[:erb] ? YAML.safe_load(ERB.new(::File.new(path, 'r').read).result) : YAML.load_file(path)
         content[Rails.env].with_indifferent_access
       else
-        fail(Error, "Configuration file not found: #{path}")
+        raise Error.new("Configuration file not found: #{path}")
       end
     end